Anolyte solution dosing for electroplating apparatus

Abstract

An electroplating apparatus comprises an anode chamber flow loop. The anode chamber flow loop comprises an anode chamber that contains an anolyte solution and an anode. A flow meter doses anolyte solution components into the anode chamber flow loop. A first valve manifold supplies components of the anolyte solution to the flow meter. The first valve manifold comprises a first shutoff valve operable to selectively fluidly couple a source of water to the flow meter, and a second shutoff valve operable to fluidly couple sources of acid and bulk inorganic plating components to the flow meter. A second valve manifold is fluidly coupled to the second shutoff valve and comprises a third shutoff valve operable to fluidly couple the source of bulk inorganic plating components to the first valve manifold, and a fourth shutoff valve operable to fluidly couple the source of acid to the first valve manifold.

1 . An electroplating apparatus, comprising:
 one or more anode chamber flow loops, each anode chamber flow loop comprising an anode chamber configured to contain an anolyte solution and an anode;   a flow meter configured to dose components of the anolyte solution into each anode chamber flow loop;   a first valve manifold configured to supply components of the anolyte solution to the flow meter, the first valve manifold comprising
 a first shutoff valve operable to selectively fluidly couple a source of water to the flow meter; and 
 a second shutoff valve selectively operable to fluidly couple sources of acid and bulk inorganic plating components to the flow meter; and 
   a second valve manifold fluidly coupled to the second shutoff valve, the second valve manifold comprising
 a third shutoff valve selectively operable to fluidly couple the source of bulk inorganic plating components to the first valve manifold; and 
 a fourth shutoff valve selectively operable to fluidly couple the source of acid to the first valve manifold. 
   
     
     
         2 . The electroplating apparatus of  claim 1 , further comprising:
 a check valve positioned between the fourth shutoff valve and the source of acid.   
     
     
         3 . The electroplating apparatus of  claim 1 , wherein the third shutoff valve is a normally-closed valve. 
     
     
         4 . The electroplating apparatus of  claim 1 , wherein the fourth shutoff valve is a normally-open valve. 
     
     
         5 . The electroplating apparatus of  claim 1 , wherein each anode chamber flow loop is a recirculating closed loop system comprising a pump configured to circulate anolyte through the anode chamber. 
     
     
         6 . The electroplating apparatus of  claim 5 , wherein each anode chamber flow loop further comprises one or more tower reservoirs. 
     
     
         7 . The electroplating apparatus of  claim 1 , wherein the source of acid comprises methanesulfonic acid. 
     
     
         8 . The electroplating apparatus of  claim 1 , wherein the third shutoff valve is configured to, when closed, allow the source of bulk inorganic plating components to be fluidly coupled to a reservoir. 
     
     
         9 . The electroplating apparatus of  claim 1 , wherein the bulk inorganic plating components comprise a dissolved metal species, and wherein the dissolved metal species precipitates in water. 
     
     
         10 . The electroplating apparatus of  claim 9 , wherein the dissolved metal species comprises tin. 
     
     
         11 . A method for operating an electroplating apparatus, comprising:
 during a startup phase,
 flushing an anode chamber flow loop with an acid from an anolyte component supply system comprising at least a first valve manifold, 
 supplying the anode chamber flow loop with a tin solution from a supply fluidly coupled to the first valve manifold, and 
 flushing the anolyte component supply system with the acid; and during an electroplating phase, 
 selectively dosing the anode chamber flow loop with acid and water via the first valve manifold responsive to signals received from one or more sensors of the anode chamber flow loop; and 
 restricting flow of the tin solution to the first valve manifold. 
   
     
     
         12 . The method of  claim 11 , wherein water is directed through the first valve manifold via a first shutoff valve, and wherein acid and the tin solution are selectively directed through the first valve manifold via a second shutoff valve. 
     
     
         13 . The method of  claim 12 , wherein the tin solution is selectively directed to the first valve manifold via a third shutoff valve comprised in a second valve manifold, upstream of the first valve manifold, and wherein acid is selectively directed to the first valve manifold via a fourth shutoff valve in the second valve manifold. 
     
     
         14 . The method of  claim 13 , wherein restricting flow of the tin solution to the first valve manifold comprises restricting opening of the third shutoff valve. 
     
     
         15 . The method of  claim 14 , further comprising:
 during a maintenance phase following the electroplating phase, draining the anode chamber flow loop,   removing restrictions on opening the third shutoff valve, and
 flowing the tin solution to the first valve manifold by opening the third shutoff valve. 
   
     
     
         16 . The method of  claim 11 , wherein supplying the anode chamber flow loop with the tin solution comprises ceasing to supply the anode chamber flow loop with the tin solution responsive to a signal received from a level sensor comprised in a tower reservoir of the anode chamber flow loop. 
     
     
         17 . An electroplating apparatus, comprising:
 one or more anode chamber flow loops;   a flow meter configured to dose components of the anolyte solution into each anode chamber flow loop;   a first valve manifold configured to supply the components of the anolyte solution to the flow meter, the first valve manifold comprising:
 a first shutoff valve operable to selectively fluidly couple a source of water to the flow meter, and 
 a second shutoff valve selectively operable to fluidly couple a source of methanesulfonic acid and tin solution to the flow meter; 
   a second valve manifold fluidly coupled to second shutoff valve, the second valve manifold comprising:
 a third shutoff valve selectively operable to fluidly couple the source of tin solution to the first valve manifold, and 
 a fourth shutoff valve selectively operable to fluidly couple the source of acid to the first valve manifold; and 
   a controller configured to control the electroplating apparatus to
 supply each anode chamber flow loop with the tin solution during a startup phase; and 
 selectively dose each anode chamber flow loop with acid and water via the first valve manifold by selectively opening and closing the first shutoff valve and the second shutoff valve while restricting supply of tin solution during an electroplating phase. 
   
     
     
         18 . The electroplating apparatus of  claim 17 , wherein the controller is configured to restrict supply of tin solution during the electroplating phase by preventing opening of the third shutoff valve via a pneumatic force. 
     
     
         19 . The electroplating apparatus of  claim 17 , wherein the controller is further configured to restrict opening of the third shutoff valve by presenting a safety warning to an operator via a user interface. 
     
     
         20 . The electroplating apparatus of  claim 17 , wherein the controller is further configured to control the electroplating apparatus to,
 during a maintenance phase following the electroplating phase,
 drain each anode chamber flow loop; 
 remove restrictions on opening the third shutoff valve; and 
 flow the tin solution to the first valve manifold by opening the third shutoff valve.